The Present Status and Future of Barrett’s Esophageal Adenocarcinoma in Japan

Background: The incidence of esophageal adenocarcinoma in Europe and the United States rapidly increased from the latter half of the 1970s and exceeded that of esophageal squamous cell carcinoma in the latter half of the 1990s, currently accounting for approximately 60% of all esophageal carcinomas. Recently, its incidence has also increased in Japan, raising concerns that it will follow a course similar to that in Europe and the United States. Summary: The incidence of esophageal adenocarcinoma in Japan was about 2% until the 1990s, but in recent years, it has risen to 6.5–7.1%. Causes include the increase in the incidence of obesity due to changes in eating habits with resultant increases in the incidence of hiatal hernia and reflux esophagitis, a decrease in the rate of Helicobacter pylori infection, and the increased interest of physicians in the gastroesophageal junction. The number of gastroesophageal reflux disease patients in Japan rapidly increased from the 1990s, which accordingly increased the number of Barrett’s esophageal adenocarcinoma patients from the latter half of the 1990s. Tabulation and analysis of 1,794 reported cases of Barrett’s esophageal adenocarcinoma in Japan showed that superficial cancers accounted for 77.6%, and that the concomitant rates of hiatal hernia and reflux esophagitis were high at 87 and 70% respectively. Key Message: The future trend in the incidence of Barrett’s esophageal adenocarcinoma in Japan will depend on the increase in the incidence of reflux esophagitis, which is essential for the development of Barrett’s esophagus and Barrett’s esophageal carcinoma. The obesity rate is lower in Japan than that in Europe and the United States, and the incidence and severity of reflux esophagitis are low. We expect that the incidence of Barrett’s esophageal adenocarcinoma in Japan will not rise as high as in Europe and the United States, and will remain below 10%.